A heat sink module for light and thin electronic equipment, where the module includes a concave top cover, and a bottom cover having on its top surface several equidistantly spaced heat conducting fins of a certain height separated by gaps. The rail also has an inner finger provided between the end fingers. A joint portion between the larger and smaller holes of each electron beam passage apertures in the central portion of the effective area is situated in the thickness-direction central portion of the mask body. The electronic mail to the second electronic mail address received by a second mail distribution service center is forwarded to a third mail distribution service center, and a replacement unit replaces a source with an acceptable electronic mail address registered in the first mail distribution service center, and the electronic mail is transmitted to the first mail distribution service center.